[Blade]

I don't think you can hold all dog owns responsible for murder. Perhaps involuntary or voluntary manslaughter. Thirty two states have a dangerous dog law, for the most part the laws are mandated by each city unless there is a state law. In 2007 there were 33 dog bite related deaths.
There are about 800,000 dog bites each year and 1 in 6 of those require ER treatment. It's the 5th leading cause for ER visits.

That said, it does sound like there are a large number of irresponsible dog owners. In North Carolina for example it is illegal to knowingly sell a dog trained to bite, except for police dogs but that is another story, typically they are taught to bite and hold. Have I ever sold a biting dog? Certainly. People were beating my doors down for them in the 80's-07, but I only trained dogs for people with a need for a protection dog.

A well trained dog is way unlikely to bite unprovoked let alone kill a human, though I know it happens. I use to tell my kids if one of our dogs bite you, you will have a spanking when we get home from the hospital, because I knew they would have to be provoked. Ya can't really say oh my dog doesn't bite. They have 42 teeth and a brain of their own.

If a person has shown they are a responsible owner then no they shouldn't face murder charges. If someone is provoking a dog, no they shouldn't face murder charges. If a person has a known biting dog and didn't keep it in a responsible fashion, then yes manslaughter. If my neighbors 3 dogs get out and kill a person and they don't have a history of viciousness, yes manslaughter.

I'm going to knock on wood here, in the past I have had over 60 guard dogs in a kennel and never remember any escaping and getting lose. I've had dogs all of my adult life at my home and have never had any get out of their pens unless I let them out. Hope it never happens. So for me it is a mixed opinion and mainly a question of circumstance.